1. Field of the Invention
This invention relates in general to electrical receptacles for receiving male plugs and, more particularly, to a self-locking electrical receptacle having a safety protector preventing a hazardous condition resulting from the partial insertion of a male prong of a plug into the receptacle.
2. Summary of the Prior Art
Electrical receptacles are in universal use to provide current to an electrical cord through the connection with a male plug having male metal prongs. The prongs of the plug are normally secured in position by frictional contact with internal members of the electrical receptacle. A typical electrical receptacle is capable of conducting electricity to the prongs of the male plug even when the prongs are partially inserted into the receptacle. The exposure of male plugs externally of the receptacle when coupled to an electrical current can present significant safety hazards to any individual who comes into any direct or indirect contact with the exposed energized metal elements of the prongs.
It is also well known that a plug within a conventional electrical receptacle can easily be withdrawn intentionally or by accident to create a disconnection of the circuit to which the receptacle is coupled. There are many circumstances under which it is desirable for reasons of convenience or safety that the connection between a plug and an electrical cord and an electrical receptacle be maintained even when significant forces are applied to disconnect the union of plug and receptacle. Several techniques have been employed in the past in an attempt to provide a more secure electrical connection between the receptacle and the plug. Most of these designs have not attained satisfactory results in use. A common problem arising from many of the prior self-locking designs is their failure to provide easy insertion and release of the lock connection. One improved design of locking the prongs of a male plug to an electrical receptacle is disclosed in U.S. Pat. No. 5,413,498 to Ursich and entitled Self-Locking Female Receptor for Electrical Cords. Although the receptor of the Ursich plug provides a highly efficient locking and release technique of the plug, it is desirable to provide improved features directed to the protection against an exposed prong and provide a lock mechanism capable of optimum locking and release within the environment of an electrical receptacle.